Memory RAM

Remember the game "memory?" It gave you a chance to test your skills of memorization and to learn colors, shapes and sizes. Computer memory is similar to this childhood favorite.

Random Access Memory RAM is a very basic short term type of memory that one may use to read and write; thus, change programs within the system. Your computer learns to keep data, but only while the system is on. Many people have to come to confuse it with its ROM, the opposite counterpart.

Read Only Memory

Also known as firmware, Read Only Memory or ROM is not lost when power is turned off (nonvolatile). Once information or data is programmed on this type of memory, it becomes cement-there to stay. It is still considered to be a random access type of memory, but one cannot write or change information already in that memory.

What makes them different?

Memory RAM has two huge subcategories: DRAM or Dynamic Random Access Memory and SRAM or Static Random Access Memory. Used in most personal computers, DRAM must be constantly refreshed (thousands of times per minute) to avoid losing data. SRAM is faster, less volatile, and is more reliable. The term "static" is used as it does not need refreshing. The disadvantages to this type of memory are that it needs more power and is more expensive. Because of the price, most SRAM is typically used as cache memory.

ROM has three subcategories: Programmable ROM (PROM), Erasable ROM (EROM), and Electrically Erasable ROM (EEROM). Each type slowly becomes more flexible to use within the system. PROM may be written into, but only one time. EROM may be erased, then reprogrammed. EEROM is the most flexible in which rewriting may occur, but only once a year.